1. Field of the Invention
The subject invention is directed to equipment for use in electroplating processes and, more particularly, to a container for holding items that are to be plated.
2. Description of the Prior Art
Electroplating processes have been used for many years to apply a metallic layer to the surface of various items. Basically, the item to be plated is suspended in a metallic solution while an electrostatic potential is applied to the item. The electrostatic potential results in an electrochemical process by which metallic ions in solution are deposited on the items. The process causes a metal layer to be deposited over the surface of the item. This process is generally used to provide a protective surface finish that is, frequently, also visually attractive.
When a metal layer of the intended thickness has developed, the items are removed from the plating solution and passed through one or more rinse baths. Thereafter, the plated item is dried.
When the items to be plated are relatively small, the items are usually placed together in a single container and plated at one time. The container is constructed of an electrically non-conductive material such as polypropylene or, alternatively, is coated with an electrically non-conductive material so that the plated metal does not accumulate on the container. Typically, the container has a number of slots, holes or other passageways so that the electroplating solution and the other fluids for cleaning and rinsing the item may pass readily to the items. When the plating process is of the type in which the containers are moved manually between the various tanks of plating, cleaning and rinsing solutions, the container is often in the general shape of a perforated bucket or basket. Examples are shown in U.S. Pat. Nos. 5,386,926 and 5,466,408.
Different items present various difficulties in the plating process. The difficulties depend on the size, shape and composition of the plated item as well as the particular metal that is being plated. In the case where many small parts are being plated, one of the problems has been that at the end of the plating process it has been difficult to "dry" the items, that is to remove residual fluids from the interstitial spaces between the items.
Various machines are commercially available to aid in this drying process. In the operation of those machines, when the container of items is removed from the last rinse fluid, the entire container is placed in one of these dryers. These dryers rotate the entire basket of items at a rapid angular velocity. The resultant radial forces acting on the entrapped fluids cause the fluids to flow toward the container wall and through the openings therein.
The dryers are produced by various manufacturers and, consequently, the dryers have a variety of mechanisms for engaging and rapidly spinning the basket. One difficulty with dryers that are manufactured for this application has been that the engagement mechanisms of all dryers are not compatible with all basket designs. For example, because many baskets are made of electrically non-conductive materials such as polypropylene, they also require reinforcing members in the bottom of the baskets so that the basket will support the weight of the plated items. In many baskets these reinforcing pieces are cross-members that are joined together at the centerpoint of the container bottom. This structure is compatible with the engagement mechanisms of some dryers, but not with others. In other baskets, the reinforcing pieces are joined in a square grid that is open at the centerpoint of the container bottom, but that has non-radial members near the outer perimeter of the basket. This structure also is compatible with the engagement mechanism of some dryers, but not with others.
Incompatibility between plating baskets and dryers has sometimes complicated user requirements for material handling of plated parts as well as basket inventory requirements. Accordingly, there was a need in the prior art for a plating basket that was sufficiently strong to support the weight of the plated items, but also that was compatible for use with all commercial dryers.